Method of acquiring status information of I/O units

Abstract

A method of acquiring status information of I / O units connected to a numerical controller capable of transmitting status information indicative of particulars of an abnormality occurred in any of the I / O units with less influence on an amount of transmittable information of input / output data. When an abnormality has occurred in the I / O unit, the I / O unit transmits an output signal with a status abnormality notifying bit set to a programmable controller (PC) in the numerical controller. The PC stores information indicative of I / O units in which the status abnormality has occurred as status-abnormality acquiring I / O unit information, in a storage device of the PC. The PC requests the status information to the I / O unit in which the abnormality has occurred according to the status-abnormality acquiring I / O unit information. In response to the request, the I / O unit transmits the status information to the PC.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a method of acquiring status information of external-signal input / output units (hereinafter referred to as I / O units) connected to a numerical controller for controlling a machine tool. In particular, the present invention relates to a method of acquiring status information indicative of abnormalities occurred in the I / O units connected to a programmable controller (PC) provided in the numerical controller.[0003]2. Description of Related Art[0004]In order to input / output information between a numerical controller and auxiliary devices of a machine tool, a plurality of I / O units are dependently connected to the numerical controller (see JP11-231923A and JP6-138916A). Usually, input information (i.e. DI data) and output information (i.e. DO data) are transmitted between the numerical controller and the I / O units. Collection of status information as internal information of the I / O units (e....

AI Technical Summary

Benefits of technology

[0006]The present invention provides a method of acquiring status information indicative of abnormality occurred in I / O units without decreasing an amount of transmittable formation of DI and DO data and without greatly increasing a total amount of the transmission due to the status information and without dependence on a user program.

[0016]It can be specified in which I / O unit an abnormality has occurred and with which input / output signal the occurrence of an abnormality of the I / O unit is notified by the PC according to the software for the PC, to shorten the time required for investigating a cause of the abnormality in the I / O units.

Problems solved by technology

Conventionally, the status information of the I / O units connected to the numerical controller is transmitted by using an area of the same frame, i.e. a part of the DI data, and therefore there is a problem that an amount of transmittable DI data is decreased by the status information data (see FIG. 17).

Further, since it is necessary to search the status information of the I / O units by analyzing every DI data, it takes a considerable time to recognize the occurrence of abnormality in the I / O units.

Also, there is a problem of increasing a total amount of transmission of the information if the status information is acquired from all of the I / O units.

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